Hydraulic pump

ABSTRACT

CASING MEANS DEFINING INLET AND OUTPUT PORTS AND HAVING A ROTOR EQUIPPED WITH IMPELLER ELEMENTS AND JOURNALED IN THE CASING MEANS OF A FIXED AXIS, THE CASING MEANS DEFINING A NORMALLY STATIONARY SEMI-CYLINDRICAL WALL SURFACE IN ROTARY SLIDING ENGAGEMENT WITH THE ROTOR. A FLOW CONTROL MEMBER DEFINES AN ARCUATE SURFACE DIAMETRICALLY OPPOSED TO THE SEMI-CYLINDRICAL WALL SURFACE AND RADIALLY MOVABLE TOWARD AND AWAY FROM THE ROTOR TO DEFINE THEREWITH AN EXPANSIBLE AND CONTRACTABLE PUMPING CHAMBER, THE FLOW CONTROL MEMBER INCLUDING LEG PORTIONS HAVING IMPELLER ENGAGING SURFACES TANGENT TO THE SEMI-CYLINDRICAL AND ARCUATE SURFACES IN ALL POSITION OF MOVEMENT OF THE CONTROL MEMBER.

March 2, 1971 w. M. SCOTT HYDRAULIC PUMP s Sheets-She efc z Filed Ma ch 19, 1969 INVENTOR. ILBE TMM Scan Q BY 4 wN W Q\ 7. ax

H wl Hi l I A 7' TOAA/EYS United States Patent 3,567,347 HYDRAULIC PUMP Wilbert Milo Scott, 808 13th Ave. W., Wiliiston, N. Dak. 58801 Filed Mar. 19, 1969, Ser. No. 808,548 Int. Cl. Ftlle 21/16; F04c 15/04, 29/10 US. Cl. 418-31 2 Claims ABSTRACT OF THE DISCLOSURE Casing means defining inlet and outlet ports and having a rotor equipped with impeller elements and journaled in the casing means on a fixed axis, the casing means defining a normally stationary semi-cylindrical wall surface in rotary sliding engagement with the rotor. A flow control member defines an arcuate surface diametrically opposed to the semi-cylindrical wall surface and radially movable toward and away from the rotor to define therewith an expansible and contractable pumping chamber, the flow control member including leg portions having impeller engaging surfaces tangent to the semi-cylindrical and arcuate surfaces in all positions of movement of the control member.

BACKGROUND OF THE INVENTION Variable displacement rotary pumps are known, having movable impeller engaging members, examples being found in such U.S. Pats. as 2,141,170, 2,356,916, 2,921,- 439 and others. The pump of Patent 2,141,170 utilizes a flexible rotor impeller engaging member to vary the displacement, others using a rigid ring-like member surrounding the rotor and movable transversely of the axis thereof. The former is quite complex as to structure, and subject to metal fatigue in the flexible portions. In the latter, when running at less than full capacity, fluid is returned by the impeller elements from the discharge to the inlet portion of the pump, resulting in a waste of pump effort and inaccuracy of volumetric delivery.

SUMMARY OF THE INVENTION An important object of this invention is the provision of a pump in which volumetric delivery can be controlled between zero and maximum pumping capacity with a high degree of accuracy and with a minimum of loss in efliciency. To this end, the pump of this invention comprises casing means having a rotor journaled therein on a fixed axis and mounting a plurality of impeller elements, the casing means defining inlet and outlet ports and a stationary semi-cylindrical wall surface rotatively slidably engaging the rotor. A flow control member defines a rigid arcuate wall surface diametrically opposite the semicylindrical wall surface and movable toward and away from substantially coaxial engagement with the rotor, the flow control member having leg portions defining opposed impeller element engaging surfaces tangent to said arcuate wall surface and to the semi-cylindrical wall surface in all positions of movement of the flow control member, the flow control member and rotor defining a pumping chamber that is expansible and contractable responsive to movements of said flow control member. The impeller elements are in the nature of flat radial vanes each comprising a plurality of thin flat blades in face-to-face sliding engagement, the rotor having radial slots for slidably receiving the vanes, each vane presenting a plurality of sealing edges to the arcuate pumping chamber wall surface, the rotor including end flanges defining radial channels in alignment with the slots for supporting opposite end portions of the vanes.

3,567,347 Patented Mar. 2, 1971 Ice FIG. 1 is a view in end elevation of a rotary hydraulic pump produced in accordance with this invention;

FIG. 2 is a view in top plan;

FIG. 3 is an enlarged transverse section taken on the irregular line 3-3 of FIG. 1;

FIG. 4 is an enlarged transverse section taken on the line 44 of FIG. 2;

FIG. 5 is an enlarged axial section taken on the line 55 of FIG. 1;

FIG. 6 is a view in section taken on the irregular line 6-6 of FIG. 4, on a reduced scale;

FIG. 7 is an enlarged detail in perspective of a sealing element;

FIG. 18 is a view in perspective of the flow control element of this invention; and

FIG. 9 is a view in perspective of an insert element of the pump casing means.

DETAILED DESCRIPTION In the embodiment of the invention illustrated, casing means, indicated in its entirety by the reference numeral 1, is shown as comprising a pair of end walls 2 and 3, side walls 4 and 5, top and bottom walls 6 and 7 secured to the end and side walls by machine screws or like fastenings 8, generally circular end plates 9 and 10 rigidly secured to the side walls 2 and 3 respectively by nut-equipped studs 11, and an insert element 12 hereinafter more fully described.

A drive shaft 13 extends transversely through the central portion of the housing 1, and is journaled in bearing bosses 14 in the end plates 9 and 10, and has splined thereon a pumping rotor 15 comprising a main body portion 16 and a pair of end flanges 17, the body portion 15 and end flanges 17 being secured together by circumferentially spaced, nut-equipped bolts 18. The end flanges 17 are journaled in circular openings 19 in the end walls 2 and 3-, and in cooperating recesses 20 in the end plates 9 and 10. The rotor main body portion 16 is formed to provide a plurality of circumferentially spaced radial slots 21 in which are slidably mounted impeller elements or vanes 22, each vane 22 comprising a plurality of thin flat blades 23 in face-to-face sliding relationship with each other. As shown in FIG. 5, the impeller vanes 22 are of greater axial length than that of the rotor main body portion 16-, the opposite ends of the vanes 22 projecting into radial slots or channels 24 in the end flanges 17, the channels 24 being in register with adjacent ones of the radial slots 21. Each vane blade 23 is provided at its opposite ends with a pair of plate-like seals 25 within the channels 24, the seals 25 being held against the ends of their respective blades 23 by seal retaining elements or bars 26 and coil compression springs 27 mounted in the end flanges 17, see particularly FIG. 5. As therein shown, as well as in FIG. 7, the seals 25 are formed to provide laterally inwardly opening notches 28 for reception of the ends of their respective vane blades 23, so that the seals 25 move radially with their respective vane blades 23.

The insert element 12. of the casing means 1 comprises a semi-circular wall 29 having an inner semi-circular wall surface 30, and a pair of laterally spaced parallel plate-like arms 31 mounted in recesses 32 in the side walls 4 and 5. As shown in FIG. 4, the insert element 12 is adjustably mounted for movements toward and away from the rotor 15 by a pair of adjustment screws 33 mounted in the side walls 4 and 5 and having screwthreaded inner ends 34 that are threadedly received in openings 35 in the arms 31. Split washers or the like 36 are mounted on the adjustment screws 33 to hold the same against longitudinal movement relative to their respective side walls 4 and 5, the adjustment screws 33 being utilized to adjustably move the semi-cylindrical wall surface 30 of the insert 12 into rotary sliding engagement of the rotor 15 therewith, and hold the insert 12 against movements radially with respect to the rotor 15. The semi-cylindrical surface encompasses the rotor 15 for substantially 180 of circular arc, the adjacent inner ends of the arms .31 having laterally outwardly and upwardly sloping surfaces 37 that are substantially aligned with adjacent laterally outwardly and upwardly sloping surfaces 38 of ports 39 and 40 in the side walls 4 and 5 respectively. For the purpose of the present example, the ports 39 and 40 may be assumed to be the inlet and outlet ports respectively of the pump. The side walls 4 and 5 are provided with suitable fittings 41 that are secured to the side walls 4 and 5 in communication with the ports 39 and 40, for connection to suitable conduit means, not shown.

A generally rectangular flow control member, indicated generally at 42, comprises top and bottom walls 43 and 44 respectively, opposite end walls 45, upper side walls 46, lower side walls 47, an arcuate partition 48, and an arcuate wall 49. As shown in FIG. 4, the partition 48 is joined at its opposite ends to the upper side walls 46, the lower arcuate wall 49 being joined to the lower side walls 47 by upwardly sloping wall portions 50 tangential to the arcuate wall 49. The opposite end walls are provided with axially aligned openings 51 therethrough that are elongated in a direction longitudinally of the flow control member, having diametrically opposite portions which coincide with the partition 48 and arcuate wall 49. The openings 51 form the inner surfaces 52 of pairs of leg portions 53 of the end walls 45 the surfaces 52 engaging diametrically opposite sides of the rotor 15 adjacent the opposite ends thereof and curved into tangential relationship with the partition 48 and the inner arcuate surface 54 of the arcuate Wall 49. It will be further noted, with reference to FIG. 4, that the leg portion surfaces 52 are also tangential to the semi-cylindrical wall surface 30 of the insert valve.

The leg portions 53 cooperate with the sloping surfaces 37 of the insert element 12 and the tangential wall portions to define fluid inlet and outlet passages 55 and 55' respectively communicating with respect to ones of the inlet and outlet ports 39 and 40. The top and bottom walls 43 and 44 respectively of the flow control member 42 cooperate with their adjacent end portions of the casing means 1 to define fluid chambers 56 and 57 that are adapted to selectively receive fluid under pressure form a suitable source, not shown, through fluid openings 58 and conduit means 59 screw threaded therein. With reference particularly to FIG. 3, it will be seen that the casing means 1, including the insert element 12, define slideways 60 for the leg portions 53 to permit upward and downward movements of the flow control element 42 in the casing means 1. As shown in FIGS. 3 and 5, the main body portion 16 of the rotor 15 projects through the openings 51, the flanges 17 rotatively engaging opposite outer surfaces of the end walls 45 of the flow control member 42 and adjacent portions of the side walls 4 and 5. Radially outwardly of the channels 24, the flanges 17 are provided with annular channels in which are mounted sealing rings in the nature of conventional 0- rings 61.

The rotor 15 and arcuate wall surface 54 of the flow control member 42 cooperate to define a pumping chamber 62 communicating with the inlet and outlet passages 55 and 55' respectively, and which pumping chamher is expansible and contractable responsive to movements of the flow control member 42 in opposite directions. By introducing fluid under pressure to the chamber 56 and removing fluid from the chamber 57, the flow control member 42 is moved in a direction to increase the distance between the arcuate wall surface 54 and the main body portion 16 of the rotor 15, to increase the displacement of the pump. Movement of the flow control member 42 in a displacement-increasing direction is limited by engagement of the partition 48 with the stationary insert element 12. Conversely, the flow control element 42 is moved toward rotary sliding engagement of the arcuate surface 54 with the main body portion 16 of the rotor 15 by adding fluid under pressure to the chamber 57 and removing fluid from the chamber 56. By causing the arcuate surface 54 to slidingly engage the peripheral surface of the rotor main body portion 16, the pump will reach a stage of Zero displacement. It will be noted that during travel between engagement with the semi-cylindrical wall surface 30 of the insert element 12 and engagement with the arcuate surface 54 of the flow control member 42, the vane blades 23 slidingly engage the surfaces 52 adjacent the opposite ends of the vanes 22. The tangential relationship between the leg portion surfaces 52 and the semi-cylindrical surface 30 of the insert element 12 in all positions of the flow control member 42 assures a smooth engagement between the outer edges of the vanes 22 and the semi-cylindrical surface 30 at all operating speeds of the rotor 15. It will be further seen, by reference to FIG. 4, that the several vane blades 23 of each vane 22 provide for multiple-edge contact between each vane and the arcuate surface 54, whereby to obtain eflicient sealing therebetween. The opposite ends of the rotor body portion 16 are formed to provide annular channels 63 that interconnect the radially inner or bottom portions of the rotor slots 21 to prevent hydraulic lock therein during radial movements of the vanes 22 in the slots 21. By extending the vanes 22 longitudinally into the radial channels 24, the vanes 22 are fully supported against pumping loads when the pump is operating at maximum capacity. As shown in FIG. 4, the seals 25 are each of the same thickness as their respective vane blades 23. Thus each group of seals 25 has snug sliding engagement with the sides of its respective slot or channel 24, each seal 25 having an axially inner edge that slidably engages the outer surface of its respective end wall 45 of the flow control member 42 to prevent fluid from entering the space between the partition 48 and the semi-cylindrical wall 29 of the insert element 12 from the bottoms of the slots 21. The upward sloping disposition of the ports 39 and 40 and cooperating passages 55 and 55' aids matcrially in obtaining a smooth flow of liquid through the pump, for maximum efficiency.

With the arrangement shown and above-described, the rotor 15 normally rotates in a clockwise direction as shown by the arrow on the motor in FIG. 4, whereby fluid is pumped from the inlet port 39 to the outlet port 40 by reversing rotation of the motor 15, the port 40 be comes the inlet port and the port .39 becomes the outlet port. However, if no provision is made for reversing direction of rotation of the rotor 15, action of the pump may be reversed by moving the flow control member 42 upwardly into rotary sliding engagement with the main body portion 16 of the rotor 15, and then turning the adjustment screws 33 in a direction to move the normally stationary insert element 12 radially out of engagement with the main body portion 16 of the rotor 15. With the present design, this reversal of pumping direction does not provide for as great efliciency as when the pump is operating in its normal forward direction. However, the pump will operate satisfactorily with this method of reversal, when such reversing is required.

What is claimed is:

1. A rotary variable displacement pump comprising:

(a) casing means defining inlet and outlet ports and having a portion defining a stationary semi-cylindrical wall surface;

(b) a pump rotor journaled in said housing means on a fixed axis and in coaxial rotary sliding engagement with said semi-cylindrical wall surface, said rotor having circumferentially spaced radial slots and including a pair of axially spaced disc like radial end flanges having opposed radial channels aligned with said slots.

(c) a flow control member having a rigid arcuate wall surface, said flow control member being movably mounted in said casing means for movements of said arcuate wall surface toward and away from substantially coaxial engagement with said rotor to define With said rotor a pumping chamber that is ex pansible and contractable responsive to said movements of the flow control member;

(d) a plurality of circumferentially spaced impeller elements radially movably mounted in said slots for engagement with said semi-cylindrical and arcuate wall surfaces and having end portions slidably disposed in opposite ones of said radial channels;

(e) said flow control member having pairs of parallel leg portions extending longitudinally of the direction of movements of the flow control member adjacent opposite ends of the rotor, the leg portions of each pair being disposed at diametrically opposite sides of the rotor and each having an impeller element engaging surface tangential to said semi-cylindrical surface and said arcuate surface;

(D said casing means defining slide Ways for reception of said leg portions;

(g) said rotor and flanges having axially inner surfaces each slidably engaging an adjacent side of said flow control member and adjacent pairs of said leg portions in all positions of movement of said flow control member;

(h) sealing elements on opposite ends of said impeller elements Within said channels;

(i) a retainer member in each of said channels;

(j) and yielding means urging said retainer members and sealing elements axially toward their respective impeller elements, said sealing elements being radial ly movable with said impeller elements and having sliding engagement with their respective retainer members and said leg portions and adjacent sides of said flow control member.

2. The rotary pump defined in claim 1 in which said flow control member compirses a pair of spaced end portions connected by said leg portions, said casing means including an insert element having a portion disposed within said flow control member and defining said semi-cylindical wall surface, and a pair of parallel arms portions at opposite ends of said semicylindrical wall surface outwardly of said flow control member, and means operative independently of said flow control member for moving said insert element radially toward and away from said coaxially sliding engagement with the rotor.

References Cited UNITED STATES PATENTS 888,779 5/1908 Berrenberg 103136HI 1,697,041 1/ 1929 Balsiger 103-120PA 2,804,017 8/1957 Wirz 103144 3,008,423 11/1961 Miller 103120PA 3,052,189 9/1962 Head 103120PA FOREIGN PATENTS 1,008,529 2/19'52 France 103-136 CARLTON R. CROYLE, Primary Examiner J. J. VRABLIK, Assistant Examiner US. Cl. X.R. 4182-5, 146 

